The present invention relates to improvements in accessories for rotary vacuum ductwork cleaning systems.
Modern buildings contain many feet (or miles) of ductwork for the HVAC (heating, ventilation, air-conditioning) system. This ductwork moves many cubic feet of air through it, often 24 hours a day, seven days a week. In addition to the air flowing through the ductwork the ductwork can contain many contaminants such as dust, fibers, pollen, hair and the like. The filtering systems used are generally unable to remove all of the contaminants from the ductwork so that regular cleaning of the ductwork itself is required.
In order to clean such ductwork, various cleaning systems have been developed. One such system which has been found to be particularly efficient is a system which utilizes a vacuum hose through which a flexible rotating cable is run. The flexible cable runs concentrically within the vacuum hose and is attached to a soft bristled brush coupled to the flexible rotating cable at the intake opening of the vacuum hose. A drive motor for rotating the flexible cable and a vacuum motor for providing a source of air flow and removing the dust picked up by the brush is located in a central power unit. An example of such equipment is illustrated in U.S. Pat. No. 4,792,363 which issued on Dec. 20, 1988 and is entitled "Vent Cleaning System." The disclosure of this patent is hereby incorporated by reference as if fully set forth herein.
The vacuum hose which has the rotary cable mounted within it is typically 35 feet, and the vacuum hose and the drive cable can slide within each other so that the drive cable becomes withdrawn within the vacuum hose, which requires the operator to retrieve the drive cable, which can be difficult when the cable withdraws fully within the vacuum hose. This typically occurs during transport of the cable and hose assembly separate from the power unit. When the cable withdraws into the hose, significant and valuable time is lost retrieving the cable, and damage to surrounding items is possible due to the aggressive retrieval method required. The present invention is directed to equipment designed to ease the handling of the vacuum hose and its drive cable to maximize the uptime of the ductwork cleaning system.
Another means for increasing the usefulness of this type of equipment is to increase its cleaning efficiency. This can be accomplished by increasing the amount of air that can flow through the vacuum hose. The equipment shown in the above-described US Patent has relatively small air intake openings at the rotating brush end which limits the amount of air (and contaminants) that can be drawn through the vacuum hose. This limits the efficiency of the ductwork cleaning machine and may also cause clogging of the intake openings. However, merely increasing the size of the inlet openings can be unsafe to the operator due to the presence of the rotating cable used to power the rotating brush. The rotating cable, if left in the open, can snag fingers or clothing, particularly at close quarters. The present invention is also directed to an improved nozzle for the vacuum hose and rotating brush which greatly increases vacuum volume but prevents the operator from being entangled by the rotating cable.
The present invention is also directed to accessories which can easily maintain the vacuum hose and cable when it is being attached to the power unit such that the equipment can be set up and taken down quickly and efficiently.
The present invention is directed to an accessory system for ductwork cleaning machines that utilize a vacuum hose having a rotating cleaning brush, the vacuum and the power for the rotating brush being supplied from a remote power unit. The accessories permit more efficient operation of the ductwork cleaning system. The first accessory is an improved nozzle for mounting the rotating brush which permits large vacuum openings without the risk of an operator being entangled within the rotating cable. A second accessory prevents the cable from withdrawing within the vacuum hose when the hose is disconnected from the power unit. The third accessory is attached to the power unit and guides the drive cable into place as the vacuum hose is attached to the power unit.